His rating should be invalid since he is a scammer. Would you trust a confirmed scammer more than a suspected one? He used his status to gain money.
The negative feeback left is sloppy to say the least.
Would I trust someone who claims to be scammed without saying what the reference is or even telling me how much they were scammed? NO.
If someone goes, I got scammed out of x
BTC and my link to prove it is here then obviously it should be taken seriously. If you can't be bothered to leave a reference link or even the value that was scammed then you're not really helping the system.